The present invention relates to a stern tube seal device.
One of prior art seal devices of this kind heretofore known has been designed so that a plurality of lip seals in close contact with and slidable relative to the shaft are arranged so as to prevent both leakings, one being leaking of sea water into a machine (into a ship) and the other being leaking of lubricating oil (bearing oil) outside the ship. However, in these prior arts, the seal relies upon the sliding portion formed by the shaft, the lip seal member or the like. If operation is carried out for a long period of time, the lip seal member tends to be worn or deformed to deteriorate the performance of the seal.